Device for cleaning the electrodes in an electrostatic dust separator



Feb. 18, 1969 H. HILGE DEVICE FOR CLEANING THE ELECTRODES IN AN ELECTROSTATIC DUST SEPARATOR Sheet Filed March 8, 1968 I lgVENTOR Feb. 18, 1969 H. HILGE 3,427,787

DEVICE FOR CLEANING THE ELECTRODES IN AN ELECTROSTATIC DUST SEPARATOR Filed March 8, 1968 Sheet 2 1 of IIIIIIIIIIIIIIIIIIII'IIIIIII'Illllflllb III 1/ 1 1/,

IIIIIIIIIIIIIIIIIIII 1 United States Patent US. Cl. 55112 Int. Cl. B03c 3/76, 3/41 1 Claims ABSTRACT OF THE DISCLOSURE A device for cleaning the vertically arranged electrodes in an electrostatic dust separator in which a horizontal beater shaft with pivoted hammer members thereon is mounted in the upper region of the separator housing parallel to a horizontal main carrier rod which has attached thereto transversely extending holder rods from which the electrical ionizing wires to be cleaned are suspended. The beater shaft when rotated by a ratchet device causes the hammer member to tap against the ends of the holder rods which in turn cause the ionizing wires to vibrate. The drive motor for the beater shaft is mounted on the outside of the cover of the separator housing and the bearings for the beater shaft which bearings also carry the main carrier, are mounted on the lower ends of vertical rods, the upper ends of which are secured to electrical insulators extending upwardly from the upper face of the cover of the separator housing.

The invention relates to a device for the cleaning of electrodes, particularly of ionizing electrodes of an elect rostatic dust separator (electrostatic precipitator), which device is provided with a beater shaft having pivoted hammer members thereon and is disposed in the upper area of the separating space and is driven from an exterior primer mover.

During the knocking of the electrodes, particularly the ionizing electrodes of an electrostatic precipitator the heretofore employed horizontally disposed beater shaft connected to a high voltage and covering several filterchannels, extended through a side wall of the filter housing and through an insulator member in the range of the filter wall so as to be electrically insulated with respect to the housing and the drive motor. This type of construction, very simple in itself, however, has the disadvantage that the required safety distance of the electrostatic precipitator from other structures or machines is substantially increased by the drive motor of the beater device which projects laterally from the vertical outer wall of the filter housing.

This causes a loss of space which particularly upon the subsequent insertion of an electrostatic precipitator in an existing industrial installation leads frequently to difficulties. The insulator member ordinarily consisting of quartz or porcelain constitutes a still further disadvantage of this known beater device. The mentioned materials are sensitive with respect to torsional or bending stresses, particularly when they arise as a result of the knocking operations in the form of sudden blows. This may lead to breaks in the insulator member.

' Furthermore, a knocking or tapping device is known, in which several hammer members pivoted to a fixedly disposed holding device are lifted by a corresponding device and after the release of a locking mechanism simultaneously strike against the electrodes or their suspension to be cleaned off. This type of knocking likewise has dis-.

advantages. Either all of the electrodes are cleaned off 3,427,787 Patented Feb. 18, 1969 simultaneously, which leads to a great concentration of dust in the gases to be cleaned off during the beating operation or, however, upon a corresponding division of the separator into several cleaning zones, several knocking devices must be disposed adjacent one another. Heretofore, additional insulators Were necessary for the positioning and fastening of the knocking device on the filter housing adjacent the insulators, and for the suspension of the electrodes. Since the bearing insulators on account of the influence of the hot gases and the deposits of dust are bound to cause troubles, it is necessary to keep the number of insulators as low as possible.

It is now an object of the invention, to provide a knocking or tapping device, which overcomes the disadvantages of the devices heretofore employed. This is accomplished in accordance with the invention by positioning of the beater shaft and the holder of the electrode carrier fixedly connected with one another, and that for the drive of the beater shaft the latter carries within the filter housing a ratchet drive which is operated from the outside by a set of levers.

The advantage of the construction of the knocking or tapping device of the present invention resides in this, that by means of the fixed connection of the beater shaft mounting with the holder of the electrode carrier, any special bearing insulators for the fastening of the knocking or tapping device are eliminated and thus the total number of the insulators required may be decreased.

The arrangement of a ratchet drive for rotating the beater shaft results in the advantage, that the insulator arranged in the set of levers extending from the filter housing to the exterior drive motor is only subjected to tension or pressure and no shock-like stresses occur. In addition, the ratchet drive permits an arrangement of the drive motor outside of the filter housing, and also farreaching possibilities of adaptation under the prevailing local conditions. It is, however, advisable to arrange the set of levers substantially perpendicular and from above. This has the advantage that for the fastening of the entire device the bearing insulators, a simple, pivotal connection may be used. The low horizontal forces encountered by a vertical actuation of the ratchet drive from above and by the great weight of the entire device and also by the fixed connection betwen the beater shaft bearing and electrode carrier are compensated to such an extent that in spite of the pivotal suspension, no lateral supports are necessary which would require an electrical insulation. And from this the drive motor may be installed in such manner as to save space on the filter cover.

In the accompanying drawings, one embodiment of the beater device of the invention is illustrated by way of example and the following description explains additional features of the invention.

In the drawings:

FIG. 1 illustrates the knocking or tapping device of the invention in a perspective view, and

FIG. 2 illustrates the details of the ratchet drive device therefor.

Referring to FIG. 1, the filter cover 1 has mounted thereon two hollow cylindrical bearing insulators 2 and 3. On these bearing insulators 2 and 3 are attached the upper ends of two vertically disposed supporting rods 4 and 5-, which extend through corresponding openings in the cover 1 of the filter. On the lower ends of these rods 4 and 5 is attached a horizontal main carrier 6 which extends transversely to the direction of the flow of the gases over almost the entire width of the filter. On the main carrier rest fixedly, the horizontal ionizing wire carriers 7 which extends in direction of flow of the gases, and from these carriers 7 are suspended the electrical ionizing wires 8. In the mounting pieces 6' for both ends of the main support 6 and above the main support 6 is rotatably positioned a horizontal beater shaft 9, on which are pivoted several hammer members 10. The main support 6 and the beater shaft 9 form a unit which with respect to the housing is electrically insulated because it is supported by the two insulators 2 and 3. Depending upon the length of the main carrier 6, there may be arranged three or more supporting rods with corresponding mounting elements for the main carrier and the beater shaft.

In the center of the beater shaft between the two supporting rods 4 and 5 is disposed a ratchet drive 11, which rotates the beater shaft 9. The hammer members 10 are disposed uniformly and offset on the shaft over the length, so that upon rotation of the beater shaft, always only one hammer member strikes against the beveled front face of the corresponding ionizing wire carrier.

The ratchet drive 11 is connected by means of a pull rod 12 with one arm of an angle lever 13, which is pivotally supported with its apex on the upper end of a vertical protective pipe 14 mounted on the cover of the filter housing. The other arm of the angle lever 13 has attached thereto one end of a connecting rod 15 which engages a crank gearing which is drive by an electromotor 16 by means of a reduction gearing. Depending upon the space conditions, however, a direct coupling of the crank gearing with the pull rod is also possible. According to the number of hammer members, it is advisable to dispose on one end of the beater shaft 9 a locking pawl mechanism 17 for preventing a reverse rotation of the beater shaft by the raised hammer members. For the sealing of the inner chamber of the filter against entry of undesired air, the crank gearing 15 is tightly sealed in a suitable box 18 (here shown in dotted lines).

FIG. 2 illustrates in more detailed manner the details of the ratchet drive 11 in accordance with the invention. The vertical pull rod 12 is provided in its upper area with a rod insulator 19 made of porcelain or quartz, in order to insulate electrically the filter housing and the crank gearing 15 from the beater shaft 9 which has a high voltage applied thereto. -In the area of the filter chamber, the pull rod is provided with a device 20 for adjusting the length of the rod, for example, with a simple turnbuckle. This turnbuckle permits in a simple manner an accurate adjustment of the ratchet drive after assembly of the knocking or tapping device. The ratchet drive consists of an indexing wheel 21 provided with teeth, which is fixedly connected with the beater shaft 9. The teeth of the indexing gear are engaged by a pawl 22. The latter is positioned rotatably on a bolt whose ends are fixed in two discs 23 disposed on both sides of the indexing gear. The discs 23 are rotatably positioned with a relatively great play, for example 3 mm., on the beater shaft 9. For mounting reasons, the discs 23, which do not have to be unconditionally circular, are made each of two halves. The rotation of the beater shaft 9 is effected by the ratchet drive, in the following manner:

Upon a downward movement of the pull rod 12, the pawl 22 is raised from the indexing wheel 21, however, the amount of raising of the pawl 22 is limited by a cam or a bolt 24 disposed above the same and which is fixed on the discs 23. After engaging the bolt 24, the two discs 23 are now rotated further in accordance with the stroke provided by means of the cam drive 13, 15. The stroke is thus so determined, that the pawl upon reversal of the direction of movement, that is, upon the upward movement of the pull rod engages on the next tooth of the indexing wheel. By a further upward movement of the pull rod, the indexing wheel 21 and the discs 23 are together rotated further. According to the distribution of the hammer members 10 on the beater shaft, a hammer member after one or several stroke movements drops against the beveled front ends of the ionizing wire carriers 7, so that through the vibrations, at the time, the ionizing wires fixed thereon are cleaned off. In this manner, one series of wires is cleaned off after the other.

Further advantages of the ratchet drive described consist now in the following:

By means of the ratchet drive, the direction of rotation of the beater shaft is definitely determined and is independent of the direction of rotation of the motor. In this way, possible disturbances are avoided, which could 0cour upon a wrong connection of the motor during the first operation. Since also by means of the combination with a crank gear, the entire drive mechanism has no abutment, but the reversal of the direction of movement of the pull bar is transmitted through the crank gear, the end and reversing connections necessary with other knocking or tapping devices are eliminated. Furthermore, since the discs 23 are positioned loosely on the beater shaft 9 during the advancing operation, that is, upon lifting of the hammers by the beater shaft through the pawl and the indexing wheel in form-locking manner, no relative movement takes place between the parts movable with respect to one another upon the movement under load. In this way an appreciable decrease in the wear of the ratchet drive is attained. By means of the cam or bolt 25 arranged below the pawl 22, care is taken that upon an upward movement the pawl and the tooth of the indexing wheel during the latching operation move only within a limited range with respect to one another, so that accordingly at the moment of the engagement of the full rotary moment, like-wise between pawl and indexing wheel, no relative movements take place, as they might be effected by cushions of dust deposited on the teeth. In this way the wear on the contact surface between pawl and indexing wheel is appreciably reduced. The drive of the ratchet drive is not limited to the example shown, as the actuation of the pawl is not limited to the one illustrated from above. The invention also is not limited to the actuation of the panel by means of a pull-rod.

What I claim is:

1. A device for the cleaning of the electrodes, particularly the ionizing electrodes in an electrostatic dust separator which is disposed in the upper area of the housing of the separator and is operated from the exterior thereof, said device comprising a horizontal rotatable beater shaft, hammer member pivotally attached thereto, a horizontal main carrier extending parallel to said beater shaft, mounting members for supporting both said heater shaft and said main carrier, vertically extending supporting rods to the lower ends of which said mounting members are secured, said housing having a cover, electrical insulator members mounted on said cover and to which the upper ends of said supporting rods are secured, horizontal electrode carriers attached to said main carrier and from which said ionizing electrodes are suspended, a ratchet drive carried by said beater shaft for rotating the same, said hammer members being arranged so as to hit the ends of said electro-carriers when said beater shaft is rotated, means for operating said ratchet device arranged on the outside of the cover of said housing, and an electrically insulated drive connection between said exterior operating means and said ratchet device.

2. A device according to claim 1, in which said ratchet device comprises an indexing wheel provided with teeth fixedly attached to said beater shaft, at least one disc loosely mounted on said beater shaft adjacent said indexing wheel, and a ratchet pawl on said disc, and pivotally connected with said electrically insulated drive connection.

3. A device according to claim 1, in which said ratchet device comprises an indexing wheel provided with teeth fixedly attached to said beater shaft, at least one disc loosely mounted on said beater shaft adjacent said indexing wheel, and a ratchet pawl on said disc, and pivotally connected with said electrically insulated drive connection and abutments (24, 25) on said disc for limiting the rotative movement of said ratchet pawl.

4. A device according to claim 1, in which said electrically insulated drive connection comprises a linkage having an electrical insulator therein.

5. A device according to claim 4, including means in said linkage for adjusting the operative length of said drive connection.

6. A device according to claim 1, in which said electrically insulated drive connection comprises a rod linkage extending in a vertical direction.

7. A device according to claim 1, including ratchet wheel on the beater shaft cooperating with a pawl mounted on one of said mounting members for preventing rotation of said beater shaft in one direction.

References Cited UNITED STATES PATENTS Egan 173-101 X Benoit -112 Drenning et a1 317-139 Elston et a1. 74-575 X Stevernagel et a1. 173-102 FOREIGN PATENTS France. Germany. Germany. Great Britain.

HARRY B. THORNTON, Primary Examiner.

D. E. TALBE-RT, JR., Assistant Examiner.

US. Cl. X.R. 

